In bestseller McGowan's breathless, at times overly melodramatic third Magdalene Line novel (after The Book of Love ), researcher Maureen Paschal, who's been feverishly investigating the “Confraternity of Saint Mary Magdalen,” uncovers juicy information about the gospel known as the Libro Rosso and the Order of the Holy Sepulcher. She heads for Florence, where her preternaturally ancient mentor, Destino, reveals the arcane past of Lorenzo de' Medici, “the great Poet Prince” and father of the Renaissance. Apparently, Lorenzo secretly married Lucrezia Donati, the “Colombina” or “little dove” featured in a number of Botticelli paintings. Maureen must also confront problems with her soul mate, Scottish oil mogul Bérenger Sinclair, after a glamorous ex claims he's fathered her son. This quasi-Christian historical fantasy confection slips back and forth in time with seamless ease. Mary Magdalene fans who enjoy wildly romantic conspiracy theories will be thrilled. (June)